by the sly的用法和樣例：
例句
- Many people attended the meeting on the sly.
許多人秘密地參加了會議。 - They decided to leave the town secretly.
他們決定秘密地離開這個城鎮。 - She must have been having lessons on the sly.
她準是暗地裡一直在上課。 - He's married but he has a girl friend on the side.
他雖有妻室，但暗地裡還有一個女朋友。 - The child had been spirited away during the night.
那孩子在夜裡被偷偷地帶走了。 - The two lovers meet only by stealth.
那兩個情人只是偷偷地會面。
